mm/compaction: more trace to understand when/why compaction start/finish
It is not well analyzed that when/why compaction start/finish or not.
With these new tracepoints, we can know much more about start/finish
reason of compaction. I can find following bug with these tracepoint.
http://www.spinics.net/lists/linux-mm/msg81582.html
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/compaction.c b/mm/compaction.c
index b12df9f..b6ede45 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -41,6 +41,8 @@
"continue",
"partial",
"complete",
+ "no_suitable_page",
+ "not_suitable_zone",
};
#endif
@@ -1049,7 +1051,7 @@
return cc->nr_migratepages ? ISOLATE_SUCCESS : ISOLATE_NONE;
}
-static int compact_finished(struct zone *zone, struct compact_control *cc,
+static int __compact_finished(struct zone *zone, struct compact_control *cc,
const int migratetype)
{
unsigned int order;
@@ -1104,7 +1106,20 @@
return COMPACT_PARTIAL;
}
- return COMPACT_CONTINUE;
+ return COMPACT_NO_SUITABLE_PAGE;
+}
+
+static int compact_finished(struct zone *zone, struct compact_control *cc,
+ const int migratetype)
+{
+ int ret;
+
+ ret = __compact_finished(zone, cc, migratetype);
+ trace_mm_compaction_finished(zone, cc->order, ret);
+ if (ret == COMPACT_NO_SUITABLE_PAGE)
+ ret = COMPACT_CONTINUE;
+
+ return ret;
}
/*
@@ -1114,7 +1129,7 @@
* COMPACT_PARTIAL - If the allocation would succeed without compaction
* COMPACT_CONTINUE - If compaction should run now
*/
-unsigned long compaction_suitable(struct zone *zone, int order,
+static unsigned long __compaction_suitable(struct zone *zone, int order,
int alloc_flags, int classzone_idx)
{
int fragindex;
@@ -1158,11 +1173,24 @@
*/
fragindex = fragmentation_index(zone, order);
if (fragindex >= 0 && fragindex <= sysctl_extfrag_threshold)
- return COMPACT_SKIPPED;
+ return COMPACT_NOT_SUITABLE_ZONE;
return COMPACT_CONTINUE;
}
+unsigned long compaction_suitable(struct zone *zone, int order,
+ int alloc_flags, int classzone_idx)
+{
+ unsigned long ret;
+
+ ret = __compaction_suitable(zone, order, alloc_flags, classzone_idx);
+ trace_mm_compaction_suitable(zone, order, ret);
+ if (ret == COMPACT_NOT_SUITABLE_ZONE)
+ ret = COMPACT_SKIPPED;
+
+ return ret;
+}
+
static int compact_zone(struct zone *zone, struct compact_control *cc)
{
int ret;
@@ -1376,6 +1404,8 @@
if (!order || !may_enter_fs || !may_perform_io)
return COMPACT_SKIPPED;
+ trace_mm_compaction_try_to_compact_pages(order, gfp_mask, mode);
+
/* Compact each zone in the list */
for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
ac->nodemask) {